Blood in Urine (Hematuria)

Some of the underlying causes of hematuria are benign, temporary states that do no lasting harm and resolve with little or no specific treatment. Some causes, however, may be critical conditions or represent a chronic condition that requires medical intervention and monitoring.

The only way to understand the seriousness of hematuria in a specific individual and to decide on an appropriate treatment is to investigate. As part of the investigation, a health practitioner will evaluate an individual's medical history, physical examination, and accompanying signs and symptoms to help determine what is causing hematuria.

This may include answering questions, such as:

Is it really blood?
One of the first questions to be asked is whether or not it is really blood that is present and/or seen in the urine.

• Reddish-brown coloring can also come from eating foods such as beets and rhubarb or taking drugs such as phenolphthalein, phenothiazine, phenacetin, phenindione, etc.
• Hemoglobinuria is the presence of hemoglobin in the urine. Some conditions cause red blood cells to break apart (hemolyze) and release hemoglobin, the iron-containing protein that gives red blood cells their color. The excess hemoglobin is eliminated through the urine, causing it to turn red or tea-colored. Hemolytic anemias, including sickle cell anemia for example, can lead to hemoglobinuria.
• Other substances produced by the body and eliminated in the urine can change the color. For example bilirubin, which is usually removed by the liver but can accumulate when it is damaged or diseased, can cause urine to be a dark amber color. This is of concern and needs to be further investigated, but it is not hematuria. Another example is myoglobin, a small, oxygen-binding protein found in heart and skeletal muscles that is filtered from the blood by the kidneys and is excreted into the urine. High levels of myoglobin can give urine a red color, making it appear as if there is blood in the urine.

Is the blood from the urinary tract?
Contaminating blood may find its way into the urine from:

• Vaginal bleeding, such as from menstruation
• Hemorrhoids

Is it due to an infection?
Infections can sometimes cause cloudy, smelly urine, painful urination, and occasionally hematuria.

• Urinary tract infections (UTIs)—mostly affect the bladder, are usually caused by bacteria or rarely viruses, fungi, or parasites, and can cause inflammation of the bladder (cystitis)
• Kidney infection—UTIs can sometimes spread to the kidneys.

Is the blood from a single isolated incident or from a known cause?
Sometimes blood may appear and then go away without the cause ever being identified. In other cases, it may be from an identifiable, resolvable or self-limited cause, such as:

• Strenuous exercise
• Fever
• Exposure to toxins, such as contrast dyes used in radiologic procedures
• Medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, or blood thinners that inhibit clotting and may increase the risk of a person having bleeding episodes with blood in the urine
• A medical procedure that physically involves part of the urinary tract, such as surgery, a kidney biopsy, or inserting a urinary catheter, can cause temporary bloody urine.
• Physical injury to the kidney or bladder, such as trauma
• An isolated incident (cause never identified)

Is the hematuria due to an inflammation or irritation of the urinary tract (or prostate in men) or due to blockage by or the passage of a kidney stone?
The following can cause blood in the urine and sometimes radiating pain, painful urination, urinary urgency, and/or urinary hesitancy:

• Urethritis—inflammation of the duct that carries urine from the bladder out of the body (urethra)
• Prostatitis—inflammation of the prostate (which surrounds the urethra in men)
• Benign prostatic hyperplasia (BPH)
• Kidney stones or bladder stones

Is it caused by kidney disease or a condition that can cause kidney damage?

• There are a variety of kidney diseases that can cause hematuria. An example is glomerulonephritis, a kidney disease associated with the filtering units in the kidneys (glomeruli).
• Diabetes and high blood pressure (hypertension) are common causes of kidney damage and can sometimes result in hematuria.
• Polycystic kidney disease is an inherited disorder that can lead to the formation of cysts in the kidneys and can lead to kidney disease.

Is hematuria due to some other disease or condition within the urinary tract?

• Structural abnormalities within the urinary tract can cause bleeding.
• Blood clots can form within the urinary tract.

Is the hematuria due to some other underlying chronic and/or inherited disorder?
This may be a disorder that affects the body as a whole (systemic) or that results in excess blood within the urinary tract, leading to hematuria. Some examples include:

• Bleeding disorders—these can lead to excessive bleeding episodes (bloody noses, bruising, prolonged bleeding, etc.) throughout the body. Examples include hemophilia and thrombocytopenia.
• Alport syndrome—an inherited condition associated with hematuria and protein in the urine
• Autoimmune disorders—with this group of diseases, the body's immune system mistakenly attacks and damages its own tissue and organs, including the kidneys.

Is hematuria due to cancer?
Cancers associated with the urinary tract and prostate can cause hematuria. These include:

• Bladder cancer
• Kidney cancer
• Prostate cancer

Many people with hematuria will not have any other signs or symptoms. Those who do typically have symptoms associated with the underlying condition. Some common examples include:

• Painful urination
• More frequent and/or urgent urination
• Abdominal and/or back pain
• Urinary hesitancy (interruption in flow, difficulty with urination)
• Fever (with infections)
• Tissue swelling (edema), such as in feet, ankles, legs
• Severe pain (with kidney stones)

Testing is performed to determine the extent, severity, and persistence of hematuria and to identify and address the underlying cause. Generally, a health practitioner will use an initial set of tests to confirm the presence of hematuria and identify or rule out some of the more common causes. Depending on those findings, as well as the affected person's signs, symptoms, and medical history, a more extensive workup may be done.

Laboratory Tests

Initial testing:

• Urinalysis—this is typically the first test performed and the primary means by which hematuria is detected or confirmed. It consists of a visual and chemical examination that can identify gross hematuria based upon the color of the urine and by a positive finding on a chemical test strip. If there are abnormal findings, then a microscopic examination is performed. Multiple urine samples may be tested. According to the American Urological Association, microscopic hematuria is defined as > 3 red blood cells seen per high powered (microscope) field (rbc/hpf) on two of three specimens. Other findings from a urinalysis, such as the presence of protein, may give clues to the cause.
• Blood tests for creatinine and urea nitrogen (BUN)—performed to evaluate kidney function; these may be ordered as part of a basic metabolic panel (BMP) or comprehensive metabolic panel (CMP).
• Complete blood count (CBC)—to evaluate blood cells and platelets; may be ordered as a general evaluation of health or when anemia, infection, or a blood cell abnormality is suspected.

Possible follow-up testing to further evaluate health of the kidneys and their function:

• Urine protein or urine albumin (microalbumin)
• Estimated glomerular filtration rate (eGFR) and/or rarely a creatinine clearance
• Cystatin C—may be used as an alternative to the blood creatinine test and to calculate eGFR
• Urine culture—performed to identify a bacterial infection when suspected
• Urine cytology—performed to look for and identify abnormal cells in the urine

Some other tests may be ordered when indicated to help further investigate the underlying cause of hematuria. Some examples include:

• Kidney stone analysis—to evaluate the composition of a kidney stone that has been passed into the urine; this test is performed on the stone itself.
• Bleeding disorder tests—including coagulation tests such as PT, PTT
• Sickle cell tests—to determine if the source of hemoglobinuria is sickle cell disease
• Hemoglobinopathy evaluation—to identify other inherited disorders affecting red blood cells
• Autoantibody testing, such as ANA, for autoimmune disorders
• Prostatic specific antigen (PSA)—to help identify prostate cancer
• Kidney biopsy—sometimes used to help determine the nature and extent of structural damage to a kidney

Non-Laboratory Tests

Testing sometimes ordered to identify abnormalities, kidney damage, kidney obstructions, tumors, and cancers may include:

• Cystoscopy
• Abdominal ultrasound
• CT scan
• Voiding cystourethrography
• Radionuclide studies

Visit RadiologyInfo.org for additional information on some of these procedures.

Frequently, no treatment is necessary for a single incident of hematuria or for hematuria that is self-limited, such as that due to strenuous exercise.

Treatments for other causes of hematuria are geared towards resolving or managing the underlying condition and treating any associated symptoms. For more on conditions that may cause hematuria and their associated treatments, see the Related Pages tab.

People who find blood in their urine should talk to their health practitioner about it and take the steps recommended to identify the significance, cause, and treatment best suited for their situation.